Original Feature may not be doing what you think it is. $OriginalFeauture is only applicable if the edit context is "UPDATE". On "INSERT" the object is null or does not exist, so the way you have written your editable expression is only valid when editing an existing feature. Also, $OriginalFeature does not change state during editing... it is fixed to the state of the feature as last submitted to the database, hence the original state of all the fields when you start an editing session will not change during the current edit session... only after submitting the feature.
Your logic can be probably just be simplified to the following
//editableExpression
if (IsEmpty($feature.field_name)) { return true };
return false;
If, however, you want to mess with $originalFeature, it is probably best to only do so if the edit context is "UPDATE". So check the editType before accessing $originalFeature.
//editableExpression
if ($editcontext.editType == 'UPDATE') {
// Lock manual editing, be sure to set equal to itself in the form calculation.
if (!IsEmpty($originalFeature.field_name)) { return false };
};
// on INSERT or on UPDATE if field is Empty
if (IsEmpty($feature.field_name)) { return true };
return false;
//formCalculation
if ($editcontext.editType == 'UPDATE') {
// Maintian the $originalFeature field value by setting it to itself
if (!IsEmpty($originalFeature.field_name)) { return $originalFeature.field_name };
};
// else if not UPDATE or original field IsEmpty on UPDATE then we do the things below.
var intersect_layer = Intersects(
FeatureSetByName($map, "Roads"),
BufferGeodetic($feature, 1, "kilometers")
);
var segment_start;
var segment_end;
var lower_dist = 1;
for (var f in intersect_layer){
var road_dist = Round(Distance(f, $feature, "kilometers"),2);
if (road_dist < lower_dist) {
segment_start= f.start;
segment_end= f.end;
lower_dist = road_dist;
}
};
return Concatenate([segment_start, ' - ', segment_end]);
- Justin Reynolds, PE
